1. Field of the Invention
The present invention relates generally to telecommunications systems. More particularly, the present invention relates to an advanced intelligent network system for providing flexible bandwidth to an Internet Service Provider commensurate with the demands for dial-up access to the Internet Service Provider's resources.
2. Background of the Invention
Over the last ten years, use of the Internet has grown rapidly. A large segment of this growth stems from an increase in individual dial-up subscribers. These dial-up subscribers use the public switched telephone network (“PSTN”) to establish connections to their Internet Service Providers (“ISPs”). FIG. 1 is a schematic diagram illustrating how these dial-up subscribers, or users, connect to their ISPs using PSTN 10. To support multiple connections, ISPs must maintain numerous telephone lines connected to modems. Rather than advertising a different telephone number for each telephone line, ISPs generally advertise a limited number of telephone access numbers. Each telephone access number corresponds to one or more telephone lines. These telephone lines may be made up of, e.g., individual POTS lines, one or more T1 lines, or Primary Rate Integrated Services Digital Network (“PRI”) lines. For simplicity, the figures and discussion herein show the connections to be made up of PRI lines.
As shown in FIG. 1, ISP 20 may provide multiple telephone access numbers, each corresponding to PRI lines connected to multi-line hunt groups (“MLHGs”). MLHGs are modem pools allowing multiple simultaneous connections to the ISP via a single telephone access number. A multi-line hunt group takes incoming subscriber calls and routes them to the first open modem in the modem pool. FIG. 1 shows four sets of PRI lines 26-29 connected to four MLHGs 22a-22d, respectively. The MLHGs are controlled by access server 23. When caller 30 dials one of ISP 20's telephone access numbers (using computer 31, modem 32 and subscriber line 33), PSTN 10 processes the call like any other call. That is, the call is routed between caller 30 and the called party (in this case, ISP 20) through one or more service switching points (“SSPs” or “switches”). If the lines corresponding to the dialed telephone access number are all busy, or “off-hook”, i.e., there are no voice 15 communications paths available, the caller gets a busy signal, which is provided by PSTN 10.
If lines are available, the ISP's switch, SSP 12 in FIG. 1, terminates the call. Access server 23 answers the call and determines whether or not the caller is a valid ISP subscriber. If the caller is valid, then access server 23 must determine which services the caller should have access to. Access server 23 queries caller 30 for information such as a username and password for use in validating caller 30 and determining caller 30's authorized services. The dialog between caller 30 and access server 23 is usually performed automatically between access server 23 and communications software operating on computer 31.
Generally, ISPs use centralized servers to store and manage their subscriber databases. Remote Authentication Dial-In User Service (“RADIUS”) server 24, having database 24a, is functionally connected to access server 23 and provides this centralized management. Thus, access server 23 collects username and password information from caller 30 and passes it on to RADIUS server 24. After RADIUS server 24 verifies caller 30's username and password, it provides access server 23 with configuration information specific to caller 30. Access server 23 uses the configuration information to provide the authorized services to caller 30. Access servers and RADIUS servers are described in more detail in commonly assigned U.S. patent application Ser. No. 09/133,299, which is incorporated herein by reference in its entirety. Additional information on access servers and RADIUS servers may be found in Rigney et al., Remote Authentication Dial-In User Service (RADIUS), Network Working Group, January, 1997, or in Rigney et al., RADIUS Accounting, Network Working Group, April, 1997.
An ISP incurs great costs for purchasing and maintaining the telecommunications infrastructure needed to operate its business. The ISP must pay its local telephone service provider (“telco”) for each telephone line maintained. Additionally, the ISP must purchase and maintain MLHGs and the associated modems for the groups. Finally, the ISP must manage and balance the load on each of its MLHGs in order to provide efficient connections for its subscribers. Due to the high cost of purchasing and maintaining the infrastructure, it is desirable for an ISP to provide only as many lines and modems as are required to accommodate its subscribers' demand.
It is well known in the art that not all subscribers connect to their ISPs at the same time. Additionally, not all subscribers connect every day, nor do they connect for the same length of time each session. For this reason, it is not cost-effective for ISPs to provide a 1:1 ratio of lines to subscribers. Instead, ISPs have developed formulas to determine the appropriate number of telephone lines required. In general, a telephone line to user ratio of at least 1:10 provides an acceptable level of service. However, as Internet usage continues to grow, it is becoming more difficult to predict the requirements for telephone lines into an ISP. Thus, a need exists for a system and method to balance the competing interests of reducing ISP costs and providing acceptable levels of service for ISP subscribers. A further need exists for a system and method providing ISPs with flexible access to increased telephone lines and modems, i.e., increased bandwidth, as the need arises to support the ISPs' customers. A system and method is needed to provide such flexible bandwidth on demand for ISP's without significantly increasing the complexity or costs for ISP operations.